CROSSLINKED POLYMERIC MICROPARTICLES; THEIR METHOD OF PREPARATION AND USE IN COATING COMPOSITIONS

Crosslinked polymeric microparticles obtained by polymerization of a mixture of polymerizable ethylenically unsaturated monomers being substantially free of monomers containing polar groups are disclosed. At least one of said monomers is a polyethylenically unsaturated crosslinking monomer free of oxyethylene groups and is present in amounts of 10 to 90 percent by weight based on total weight of said polymerizable ethylenically unsaturated monomers. The crosslinked polymeric microparticles are prepared by aqueous emulsion polymerization techniques in the absence of polyester emulsifier. The microparticles are separated from the aqueous polymerization medium and converted into organic medium by azeotropic distillation. The microparticles are useful in organic solvent-based high solids coating compositions and can be used in color coats, clear coats or composite color-clear coatings where the crosslinked polymeric microparticles can be contained in the color coat and/or in the clear coat. The crosslinked polymeric microparticles when present in additive amounts in such coating compositions improve the sag resistance and the metallic pigment pattern control of the coating and do not detract from the overall desirable properties of the coating.